Laser tracker based robotic assembly system for large scale peg-hole parts

The process of peg-in-hole insertion is the most typical problem in robotic assembly research. In this paper, a laser tracker based robotic assembly system is proposed for the insertion of large scale peg-hole type parts with heavy weight. A flexible end-effector with several claws, motivated by stepper motors, is designed to grasp the shaft part. Laser interferometry guidance methodology is utilized in the assembly task to calibrate the geometrical characteristics (cylinder surfaces, end points and axes) of parts, and also to eliminate the uncertainty of position and orientation due to the flexible grippers, thus enhancing the absolute positioning accuracy of the assembly system. The force analysis of different stages in the assembly process is performed and the results are validated by assembly experiments.